Method for quickly measuring precision of reflection face of radiotelescope

Abstract

The invention relates to a method for quickly measuring the precision of a reflection face of a radiotelescope. The method can effectively solve the problems that in the large-caliber radiotelescope reflection face precision measurement process, measurement time is long, measurement precision is low, the angle of pitch of measurement is fixed, and external hardware equipment is needed for assistance. According to the method as a special phase retrieval microwave holography method, it is only needed that the amplitude of an antenna aperture field is measured, and the retrieval of the phase of the antenna aperture field is carried out according to a certain method. In the method, any stable astronomical radio source can serve as a signal source, and beam patterns are scanned under the antenna focusing condition or the antenna out-of-focus condition through an astronomic receiving machine and a terminal (power radiometer); an antenna aperture phase model is built according to the Zernike polynomials function, iterative operation is carried out on the residual error of a model value and a measured value through the minimization algorithm, and therefore the optimal solution corresponding to the minimum residual error vector is obtained to obtain a Zernike polynomials coefficient, backstepping is carried out to obtain the hole aperture phase distribution of an antenna, and the precision of the reflection face of the radiotelescope can be obtained.

Description

technical field [0001] The invention relates to a method for quickly measuring the precision of a radio telescope reflection surface. Background technique [0002] The accuracy of the reflective surface of a radio astronomy telescope is an important indicator that affects its performance. It not only affects the observation efficiency of the radio telescope, but also determines the shortest wavelength that the radio telescope can work. In order to facilitate manufacturing and installation, the reflective surface (generally referred to as the main reflective surface) of a large-aperture radio telescope is usually spliced ​​by multiple single panels. During construction, electronic level installation, photogrammetry initial adjustment and microwave holographic fine adjustment can be used, etc. A series of technical means, so that the surface shape accuracy of the reflective surface of the radio telescope at a certain pitch angle can reach the design index. But when working, b...

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Problems solved by technology

[0008] 1. The gain of the reference antenna is low, and long-time integration is required. In order to calibrate the phase, it is necessary to periodically point to the signal source during the scanning process to obtain a phase reference, thereby reducing the scanning efficiency of the antenna and causing a long measurement time. question;

[0009] 2. Since the direct measurement of the phase distribution of the antenna aperture field requires a reference antenna and a correlator to obtain the reference phase, the complexity and hardware cost of the system are greatly increased;

[0010] 3. Since the gain of the reference antenna is too low, only geosynchronous satellites can be used as its signal source. In this case, the antenna pitch angle is a fixed value, and measurement at any pitch angle cannot be realized

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